The present invention concerns an intake pipe for intake gas, in particular intake air, of an internal combustion engine, in particular of a motor vehicle, comprising at least one intake pipe channel and at least one flap unit for selectively opening or closing at least one intake pipe channel. The flap unit has a flap shaft and at least one flap that is fixedly arranged on the flap shaft and is arranged in the intake pipe channel within a hollow insert body that is open at opposite end faces. The flap shaft extends in radial direction relative to an insert body axis through circumferential walls of the insert body. The insert body is rotatable on the flap shaft.
US 2010/0071977 A1 discloses an intake pipe of an internal combustion engine, in particular of a motor vehicle, comprising at least one intake pipe channel and at least one flap unit arranged in an intake pipe for selectively opening or closing the channel. The flap unit has a flap shaft and at least one flap that is arranged fixedly on the flap shaft. For each flap a cylindrical bearing bracket is provided through which the flap shaft passes in radial direction. The flap is arranged within the bearing bracket. The bearing bracket is slidably supported on the flap shaft in axial direction relative to the flap shaft. Also, the bearing bracket is supported on the flap shaft so as to be rotatable about it.
The invention has the object to design an intake pipe of the aforementioned kind in which a flow characteristic of the intake gas flowing through the intake pipe channel and the insert body is further improved. In particular, a flow course through the insert body is to be improved. Moreover, possible pressure losses between the gas inlet side and the gas outlet side of the insert body are to be reduced in particular.